A video camera is widely used by general users to enjoy capturing images during a variety of events or travels. However, users generally simply store captured images without modification after viewing it only once or without viewing it. The primary reason is that unmodified captured images are raw materials that are not suitable for viewing with enjoyment. The reason why the captured images without modification are not suitable for viewing with enjoyment is, for example, that images captured by a video camera frequently include bad scenes where a person cuts in front of the video camera during capturing or where someone's head enters a screen of the video camera at the lower side of the screen. To obtain attractive content that is suitable for viewing with enjoyment, it is necessary to perform an editing process. However, since editing requires time and effort, users often give up editing captured images and consequently leave the captured images unmodified.
To perform editing, first, it is necessary to check all captured images to select scenes to be retained and unnecessary scenes to be removed. Thereafter, when needed, the images are modified or processed and captions are finally inserted into the images or transition effects are applied to joints. The insertion of captions that is performed finally and the application of transition effects are enjoyable in many aspects since they are creative processes. However, the initial process of selecting scenes requires a lot of time and is not interesting since it is necessary to view all captured images that are to be edited. Thus, at this initial stage, users often lose interest and give up editing the captured images.
To easily select images of unnecessary scenes from among images that are being edited, it is necessary to identify a blocker (i.e., an object which blocks the front of a subject) in each image. In one conventional method for identifying a moving object as such a blocker, an image memory for storing image signals obtained by capturing images using a camera is installed, the magnitudes of motion vectors of images between image frames are measured to detect a moving region, coordinates of the detected moving region on the camera image are converted into real space coordinates, and at least one of the size, the aspect ratio, or the moving speed of the object at the converted real space coordinates is compared with those of a table, in which features of a plurality of objects are previously registered, to identify the type of the moving object (Japanese Patent Application Publication No. 2002-027449).
In another known method, a motion vector of an object that is in motion in an image is extracted, object blocks are extracted based on motion indices, and statistical values thereof are obtained and are then compared with reference values to determine a target moving object (Japanese Patent Application Publication No. 09-252467).
In a known method for identifying a blurry region in a captured image, the area of a region having a focusing level below a predetermined level is detected according to the contrast ratio and the region is determined to be a blocker region if the detected area is larger than a predetermined area (Japanese Patent Application Publication No. 2005-136727).
However, these conventional methods for identifying a moving object or a blur portion have problems in that it is necessary to use camera information and to extract and track feature points and it is also not possible to identify an object from a general image signal with sufficient accuracy.